The invention relates to improvements in apparatus for moving pivotable gates or turnstiles, swingable door panels, pivotable shackles or straps and the like. More particularly, the invention relates to improvements in apparatus which can serve to move one or more components between predetermined first and second end positions.
Heretofore known apparatus of the above outlined type are normally provided with a frame member for a prime mover, with a frame member for the output element which carries the pivotable component or components, a frame member for motion transmitting parts which establish an operative connection between the prime mover and the output element, and a frame member for the spring or springs which are or can be provided to bias the output element to one of its positions. The motion transmitting parts can comprise one or more levers and/or links, and the springs can be connected to a coupling lever which is affixed to the output element so that the springs are capable of turning the output element when the prime mover permits such angular movement of the output element. Reference may be had, for example, to German Offenlegungsschrift No. 2 254 231 of Weiss which describes an apparatus serving to move the panels of swinging doors. Such apparatus can also be used to pivot gates or other types of barriers, e.g., at the entrances to ski lifts, in supermarkets and elsewhere.
A drawback of the just described conventional apparatus is that its space requirements are excessive and that the installation of such apparatus is a complex and time-consuming operation. This is due, in part, to the fact that the apparatus employs a number of discrete frame members. The support for such apparatus must be provided with one or more doors which afford access to the parts and contribute to the bulk and cost of the entire assembly. Moreover, it is difficult, if not impossible, to assemble the entire apparatus at the manufacturing plant; this also contributes to the cost of installation, inspection, repair and replacement.
German Utility Model No. 79 30 545 of Vereinigte Beschlagfabriken Gretsch & Co GmbH discloses an apparatus which can actuate the panel or panels of a swinging door and comprises an electric motor which is installed in a housing and transmits motion to a worm drive. The housing includes an elongated base plate and a hood and constitutes a hollow prismatic body. The apparatus further includes a two-stage stepdown gear transmission having at least four gears. The output shaft, an intermediate shaft and a third shaft of the apparatus are installed in a housing block which is secured to the base plate. All this contributes to the bulk and cost of the apparatus.
German Offenlegungsschrift No. 32 09 608 of Weiss discloses another apparatus which can be used to move the panels of swinging doors, to move pivotable gates and for other purposes. The inventor emphasizes the design of the control circuitry for the electric motor. The motor and numerous other parts are mounted in an elongated housing.